Effects Of Mechanical Properties Of The Bridge When Considering The Interaction Of The Deck And Steel Truss

Cable-stayed bridge is also called the stayed bridge, belongs to the combination system bridges, which is a kind of combined structure system by the pressure of the tower, tension of the cable and bending of beam body. The steel girder cable-stayed bridge’s girder is composed of orthotropic steel bridge panel and steel truss girders. Due to its special form of space structure meet the needs of the arrangement of double deck girders, and the big bending rigidity, efficient performance is outstanding, so is widely used in combined highway and railway bridge. But the reference literature about this kind of structure mechanics bridge’ research is very little, the mechanical properties of bridges about considering the interaction of bridge deck and steel truss is unclear. For a comprehensive understanding of its mechanical characteristics, the paper will be studied about this.This paper’s engineering background is East Gate Bridge,and around the steel girder cable-stayed bridge are described in three aspects. The first part mainly introduces the development history of cable-stayed Bridges and steel girder cable-stayed bridge, and the research means and methods, the second part mainly introduces the use of Midas Civil software modeling process of the bridge, analyzes the problems in the process of modeling, how to correctly select the element properties, the connection problems of member and the bridge’s boundary conditions, load arrangement, etc. The third part is the core part of the paper, in the early modeling process, through two different ways to connect the deck and steel truss, to simulate the deck and steel truss joint action or not. And then contrastive analysis of the force condition about top chord、lower chord、the longitudinal beam 、 deck 、 web member and stay cable with the dead load state and operation state, the difference of vibration mode、natural frequency under the action of dead load and vertical deflection、rotation angle under the action of live load, And get the following conclusions: ①When considering the interaction of deck and steel truss, the internal force of main truss elements is smaller than it don’t consider the interaction, and the internal force of deck is bigger. The research shows that the deck not only as a supporting structure of automobile wheel load, but also as part of the main girder which share the internal force. ②Internal forces of web member and stay cable have little effect when considering the interaction or not. ③Natural frequency when considering the interaction of deck and steel truss is bigger than it don’t consider the interaction, vertical deflection、rotation angle under the action of live load is smaller than the latter, the research shows that the interaction of the deck and steel truss can increase the stiffness of the bridge, is beneficial to the force of the bridge.